1. Field of the Invention
This invention relates, generally, to devices that enable people having low vision to read printed documents. More particularly, it relates to a camera in an electronic magnifier requiring symmetrical illumination when used in contact with or near a target object such as a printed document.
2. Description of the Prior Art
Using a magnifying glass to enlarge print is problematic. The glass must be positioned a specific distance from the paper to obtain optimal magnification, and the paper must be well-illuminated.
The art has therefore moved in the direction of using video cameras to view the print and to drive a liquid crystal display (LCD) that displays the camera output in enlarged form. Such systems typically include a magnifier system where magnification is determined by the distance to the object to be viewed, the ratio of sensor to display size, and optical features of the camera. In the future, the optical features of the camera may perform the magnification.
Uniform, symmetrical illumination of the object being viewed has remained problematic. Thus, there remains a need for a low vision reader having an LCD display of a well-illuminated object.
Conventional low vision readers require a user to either hold the reader above the document or to use clumsy stands to hold the reader above the document.
Thus there is a need for a low vision reader that does not require a user to hold the reader in hovering relation to a document, either with or without a stand.
However, in view of the prior art taken as a whole at the time the present invention was made, it was not obvious to those of ordinary skill how the identified needs could be fulfilled.